The proposed research is directed at attempts to isolate bioactive factors from demineralized adult bone. Such factors could be extremely useful in aspects of fracture repair or periodontal disease. I envision restoration of severe bone loss due to periodontal disease would be a major use for bioactive factors which originate from demineralized bone. The studies proposed here center on efforts to purify three bioactivities: (1) the stimulation of the conversion of mesenchymal cells into chondrocytes; (2) the inhibition of mesenchymal cell development into chondrocytes and (3) mitotic and anti-mitotic activities. These three activities are associated with the in vivo response of demineralized bone matrix. Importantly, cell culture bioassay for these activities have been designed using stage 24 chick embryo limb bud mesenchymal cells. These cell cultures offer a reasonably fast, reproducible and reliable assay which is sensitive to Mug quantities of partially purified preparations from demineralized bone. The goals of this research are to purify and characterize these bioactive factors and study their modes of action in pre-skeletal and non-skeletal cell populations. Monoclonal antibodies can be utilized to determine cytological localization, site of synthesis and species cross-reactivity of these factors. Immobilization of water-soluble chondrogenic factors onto biocompatible implant devices can be used for in vivo stimulation of cartilage and/or bone tissue at ectopic sites. The development of clinically useful "delivery vehicles" for regeneration of skeletal tissue is proposed.